The chassis of electronic devices, such as notebook personal computers (laptop PCs), tablet personal computers (tablet PCs), smartphones, etc., should be light in weight, small in thickness and high in strength. Accordingly, the popular choice of material for chassis of electronic devices is a laminated sheet having an intermediate layer made of a foamed material sandwiched between prepreg sheets (fiber reinforced resin sheets) prepared by impregnating reinforced fibers such as carbon fibers with a thermosetting resin such as an epoxy resin.
When such a laminated sheet is to be used in the chassis of laptop PCs, it is requested to perform machining of a desirable shape such as a wall part at least on a peripheral edge part of the laminated sheet. However, since the laminated sheet is configured by using a hard fiber reinforced resin sheet, the laminated sheet is low in degree of freedom of shape machining such as bending.
When configuring the chassis by coupling and fixing the member for chassis to the other member for chassis, it is necessary to form a nut that configures a female screw by insert-molding in a thermoplastic resin part that has been bonded to the laminated sheet. However, with such a configuration, since the nut is arranged in the thermoplastic resin part that has been bonded to a part located outside of the external-form end face of the laminated sheet, when a shock and external force are applied to the chassis, the shock and external force are transmitted from a screw that clamps together the two members for chassis directly to the thermoplastic resin part via the nut. As a result, there is a tendency that the load on the thermoplastic resin part which is inferior in strength to a laminated sheet part having a high strength or a bonded interface between the thermoplastic resin part and the laminated sheet is increased. In particular, when the nut that is formed by such insert-molding has been utilized for fixing a hinge that couples together two chassis of a laptop PC, it is feared that when the laptop PC is dropped, most of the load of the laptop PC will be applied to the nut and causes the thermoplastic resin that holds the nut to be broken.
Consequently, it would be preferable to provide an improved chassis member with a higher strength.